1. Intelligence intercepts foretold of the September 11 attacks with warnings such as "tomorrow is zero hour." U.S. intelligence intercepted communications on Sept. 10 in which suspected Al Qaeda operatives said "tomorrow is zero hour" and referred to the beginning of "the match," but these probably were not references to the September 11 attacks, but to a military offensive in Afghanistan.

2. Zacarias Moussaoui was detained a month before the attacks in Minnesota after he tried to enroll in an area flight school with the peculiar request to learn how to take off - but not land - a Boeing 747. Instead, Moussaoui stood out because, with little knowledge of flying, he wanted to learn how to take off and land a Boeing 747 - which is not an aircraft generally flown by a beginner.

3. The September 11 hijackers used box cutters as weapons. Instead, the Commission said it was more likely the hijackers used "Leatherman" utility knives that have several tools and a long, sharp blade that locks into position - which at least two of the hijackers probably purchased and FAA guidelines permitted on board. Box cutters were banned.

4. Saudi nationals including relatives of Al Qaeda leader Osama bin Laden were allowed to leave the country unchecked on chartered jets in the immediate aftermath of the attack, while all other flights were still grounded. In fact, six chartered flights carrying 142 Saudis did leave the country in the days after the attacks, the report said, and one plane had 26 passengers, "most of them relatives" of Bin Laden. The Commission cleared the government of any wrongdoing, saying that all of the passengers were screened by the FBI and other agencies, and that none of the planes left before commercial airspace was reopened.